Knowledge of how the climate has varied in the past is necessary if we are to understand the causes and mechanisms behind today's climate changes and the impact of human activities on them. Using diatoms in sediment from Swedish mountain lakes, Christina Jonsson, Department of Physical Geography and Quaternary Geology at Stockholm University, has studied changes in atmospheric circulation.
Northern Sweden is sensitive to changes in atmospheric circulation since the region is affected by air masses of differing origin, from the North Atlantic, the Baltic, and the Arctic. Depending on which air mass dominates, the temperature and the amount of precipitation changes. The composition of the various oxygen isotopes 160 and 180 in precipitation is also impacted.
"Changes in precipitation influence in turn the oxygen content of lake water and are picked up by tiny diatoms living in the lakes. Shells from these algae are preserved in the sediment on the bottom of the lake and can be analyzed to reveal changes in circulation and variations in climate since the latest ice age, that is, during the last 10,000 years," says Christina Jonsson.
The dissertation uncovers both long-term changes in circulation and shorter periods of alte red circulation patterns. About 500 years ago a change in climate occur red when the amount of winter precipitation increased.
"This change in circulation probably marks the beginning of the so-called little ice age in this region," says Christina Jonsson.
The dissertation enhances our knowledge of how changes in atmospheric circulation have impacted the climate in Sweden over the last 10,000 years.
Title of dissertation: /Holocene climate and atmospheric circulation changes. Interpretations from lacustrine oxygen isotope records/.Further information
Maria Sandqvist | idw
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy